Issues With Discovery Plugin and DHCP

Hello, I’m trying to set up the Discovery plugin v 11.0 with Foreman 1.17 on CentOS 7.4. I have installed everything and set up the plugin as described in the plugin docs. Everything seems to be correct. However, newly started nodes that I expect to get an IP and get the discovery image aren’t being responded to by the DHCP server.

May 15 17:48:02 foreman dhcpd: DHCPDISCOVER from $my_mac via eth0: network $my_network: no free leases

This is what I would normally see with nodes that had not yet been added to Foreman. And of course if I manually create a host entry for a host with $my_mac, it boots as expected. But for discovery I was expecting new nodes to provision with the discovery instance without the need for manual creation of host entries and entering MAC addresses. I suspect there is some additional change I need to make to Foreman to configure the DHCP server to hand out addresses to new unknown hosts? It definitively seems like there’s something simple I’m just missing, so any help would be appreciated.